pci: split the function providing uio device and mappings

Add a new function pci_get_uio_dev() that parses /sys/bus/pci/devices
to get the uio device associated with a PCI device. This patch just
moves some code that was in pci_uio_map_resource() in the new function
without any functional change.

Thanks to this change, the next commit will be easier to understand.
Moreover it improves readability: having smaller functions help to
understand what pci_uio_map_resource() does.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>

diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
index 074d7cf..e6216c5 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_pci.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
@@ -460,34 +460,20 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
        return -1;
 }
 
-/* map the PCI resource of a PCI device in virtual memory */
-static int
-pci_uio_map_resource(struct rte_pci_device *dev)
+/*
+ * Return the uioX char device used for a pci device. On success, return
+ * the UIO number and fill dstbuf string with the path of the device in
+ * sysfs. On error, return a negative value. In this case dstbuf is
+ * invalid.
+ */
+static int pci_get_uio_dev(struct rte_pci_device *dev, char *dstbuf,
+                          unsigned int buflen)
 {
-       int i, j;
+       struct rte_pci_addr *loc = &dev->addr;
+       unsigned int uio_num;
        struct dirent *e;
        DIR *dir;
        char dirname[PATH_MAX];
-       char filename[PATH_MAX];
-       char dirname2[PATH_MAX];
-       char devname[PATH_MAX]; /* contains the /dev/uioX */
-       void *mapaddr;
-       unsigned uio_num;
-       unsigned long start,size;
-       uint64_t phaddr;
-       uint64_t offset;
-       uint64_t pagesz;
-       ssize_t nb_maps;
-       struct rte_pci_addr *loc = &dev->addr;
-       struct uio_resource *uio_res;
-       struct uio_map *maps;
-
-       dev->intr_handle.fd = -1;
-
-       /* secondary processes - use already recorded details */
-       if ((rte_eal_process_type() != RTE_PROC_PRIMARY) &&
-               (dev->id.vendor_id != PCI_VENDOR_ID_QUMRANET))
-               return (pci_uio_map_secondary(dev));
 
        /* depending on kernel version, uio can be located in uio/uioX
         * or uio:uioX */
@@ -525,8 +511,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
                errno = 0;
                uio_num = strtoull(e->d_name + shortprefix_len, &endptr, 10);
                if (errno == 0 && endptr != (e->d_name + shortprefix_len)) {
-                       rte_snprintf(dirname2, sizeof(dirname2),
-                                "%s/uio%u", dirname, uio_num);
+                       rte_snprintf(dstbuf, buflen, "%s/uio%u", dirname, uio_num);
                        break;
                }
 
@@ -534,15 +519,48 @@ pci_uio_map_resource(struct rte_pci_device *dev)
                errno = 0;
                uio_num = strtoull(e->d_name + longprefix_len, &endptr, 10);
                if (errno == 0 && endptr != (e->d_name + longprefix_len)) {
-                       rte_snprintf(dirname2, sizeof(dirname2),
-                                "%s/uio:uio%u", dirname, uio_num);
+                       rte_snprintf(dstbuf, buflen, "%s/uio:uio%u", dirname, uio_num);
                        break;
                }
        }
        closedir(dir);
 
        /* No uio resource found */
-       if (e == NULL) {
+       if (e == NULL)
+               return -1;
+
+       return 0;
+}
+
+/* map the PCI resource of a PCI device in virtual memory */
+static int
+pci_uio_map_resource(struct rte_pci_device *dev)
+{
+       int i, j;
+       char dirname[PATH_MAX];
+       char filename[PATH_MAX];
+       char devname[PATH_MAX]; /* contains the /dev/uioX */
+       void *mapaddr;
+       int uio_num;
+       unsigned long start,size;
+       uint64_t phaddr;
+       uint64_t offset;
+       uint64_t pagesz;
+       ssize_t nb_maps;
+       struct rte_pci_addr *loc = &dev->addr;
+       struct uio_resource *uio_res;
+       struct uio_map *maps;
+
+       dev->intr_handle.fd = -1;
+
+       /* secondary processes - use already recorded details */
+       if ((rte_eal_process_type() != RTE_PROC_PRIMARY) &&
+           (dev->id.vendor_id != PCI_VENDOR_ID_QUMRANET))
+               return (pci_uio_map_secondary(dev));
+
+       /* find uio resource */
+       uio_num = pci_get_uio_dev(dev, dirname, sizeof(dirname));
+       if (uio_num < 0) {
                RTE_LOG(WARNING, EAL, "  "PCI_PRI_FMT" not managed by UIO driver, "
                                "skipping\n", loc->domain, loc->bus, loc->devid, loc->function);
                return -1;
@@ -551,7 +569,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
        if(dev->id.vendor_id == PCI_VENDOR_ID_QUMRANET) {
                /* get portio size */
                rte_snprintf(filename, sizeof(filename),
-                        "%s/portio/port0/size", dirname2);
+                        "%s/portio/port0/size", dirname);
                if (eal_parse_sysfs_value(filename, &size) < 0) {
                        RTE_LOG(ERR, EAL, "%s(): cannot parse size\n",
                                __func__);
@@ -560,7 +578,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
 
                /* get portio start */
                rte_snprintf(filename, sizeof(filename),
-                        "%s/portio/port0/start", dirname2);
+                        "%s/portio/port0/start", dirname);
                if (eal_parse_sysfs_value(filename, &start) < 0) {
                        RTE_LOG(ERR, EAL, "%s(): cannot parse portio start\n",
                                __func__);
@@ -585,7 +603,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
        memcpy(&uio_res->pci_addr, &dev->addr, sizeof(uio_res->pci_addr));
 
        /* collect info about device mappings */
-       if ((nb_maps = pci_uio_get_mappings(dirname2, uio_res->maps,
+       if ((nb_maps = pci_uio_get_mappings(dirname, uio_res->maps,
                        sizeof (uio_res->maps) / sizeof (uio_res->maps[0])))
                        < 0)
                return (nb_maps);